(define (vector->list v)
  (let ((l (vector-length v)))
    (let loop ((i 0))
      (if (= i l)
          '()
          (cons (vector-ref v i)
                (loop (+ i 1)))))))

(define (list->vector l)
 (let ((len (length l)))
   (let ((v (make-vector len #f)))
    (let loop ((i 0) (l l))
      (if (= i len)
          v
          (begin (vector-set! v i (car l))
                 (loop (+ i 1) (cdr l))))))))
